The present invention relates to a stream processor handling a plurality of streams.
In recent years, there have increased cases of broadcasting, transmitting and storing images, voice and data in the form of digital data. For example, in digital TV broadcasting, DVD drives, digital VTRs, digital video cameras, IEEE 1394 devices and the like, video signals, audio signals and data in data broadcasting, electric program guide (EPG) and the like are collectively broadcast, transmitted, processed and stored as streams. Data formats for such streams vary with applications. For example, digital TV broadcasting and digital VTRs adopt transport streams defined by MPEG Systems Standard (ISO/IEC 13818-1). DVD drives adopt program streams defined by MPEG Systems Standard (ISO/IEC 13818-1). A DV format is adopted for transmission of recorded data from a digital video camera via an IEEE 1394 bus. Therefore, processing unique to each of these data formats is required.
Under the above circumstances, there has emerged digital AV equipment provided with a plurality of functions, in addition to conventional single-function equipment. For example, a digital TV receiver provided with an IEEE 1394 interface has functions of “receiving and displaying a program on the air”, “receiving a program on the air and recording the program in an external storage device connected via an IEEE 1394 bus”, and “playing back a program from an external storage device connected via an IEEE 1394 bus and displaying the program”. A stream input into this digital TV receiver includes a “stream of a program on the air” and a “stream of a program played back from an external storage device connected via an IEEE 1394 bus”. A stream output from the digital TV receiver includes a “stream of a program to be recorded in an external storage device connected via an IEEE 1394 bus”. In this way, a plurality of streams are input into and output from the digital TV receiver.
A digital TV receiver includes a transport decoder as an LSI for processing a stream. The digital TV receiver also includes a stream input/output interface (for example, an IEEE 1394 interface) for passing a stream input from outside to the transport decoder and outputting a stream processed by the transport decoder to outside, as another LSI independent from the transport decoder LSI. Connection between these LSIs on a printed board is optimized depending on an application system. It is however impossible to assume all possible uses in the future, and thus the range of future applications is limited by assumption during the system design.
With recent advances in integration of LSI circuits, it has become possible to mount a transport decoder and a stream input/output interface as one LSI. In this situation, it has become necessary to assume during the design of the LSI, both the application range of the LSI to be adapted in the future during which the LSI will be kept used and functions expected to be realized by a system using the LSI.
With advances in audio/video digitization and networking, the number of types of the stream input/output interfaces has increased, and the number of streams to be processed simultaneously has increased. In addition, the processing of streams has been diversified.